An agent chat turned into a skill, and then it QA'd itself

I had a simple index.html page, a marketing site for a client in Spanish. They asked an English version too, so I opened the chat to Claude’s Opus 4.5 model and asked it to create a near-identical en/index.html with content translated. Easy peasy. I opened both files side by side and skimmed, they looked the same with lines in different languages. But I’m used to testing changes, and agents find…